According to investigators at a briefing in Taipei, the plane ran into trouble just 37 seconds after taking off from Taipei's Songshan airport.
Thomas Wang, director of the Aviation Safety Council, said the pilot announced a "flame-out", which can occur when the fuel supply to the engine is interrupted or when there is faulty combustion.
However, he said there was no flame-out, and the right engine had actually shifted into idle mode without the oil pressure having changed.
"The plane flashed a flame-out signal for one of the two engines at 10:53:28 when the plane climbed to an altitude of 1,200ft, triggering a warning," AFP news agency quoted Mr Wang as saying.
"Then the other [left] engine was shut down manually. The pilot tried to restart the engines but to no avail. That means that during the flight's final moments, neither engine had any thrust. We heard 'Mayday' at 10:54:35," he added.
The plane, which had been bound for Taiwan's Kinmen Island, crashed into the Keelung River just 72 seconds later.
BBC News - TransAsia GE235: Taiwan plane crash engines 'lost power'
https://uk.news.yahoo.com/pilots-bod...e.html#SgCxa19